#include <Keypad.h>
byte row = 4;
byte col = 4;
char keys[4][4] = {
{ '1', '2', '3', 'A' },
{ '4', '5', '6', 'B' },
{ '7', '8', '9', 'C' },
{ '*', '0', '#', 'D' }
};
byte rowpin[4] = { 9, 8, 7, 6 };
byte colpin[4] = { 5, 4, 3, 2 };
Keypad mykeypad = Keypad(makeKeymap(keys), rowpin, colpin, row, col);
void setup() {
Serial.begin(9600);
}
void loop() {
char presskey = mykeypad.getKey();
if (presskey) {
Serial.println(presskey);
}
}